feat: initial Speedboard implementation

sitespeed.io web UI with Express/Pug/SQLite — port 3132.
Includes job queue, SSE live log, full metrics dashboard,
site history, CO2/axe/CWV sections, and Docker support.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.js

@@ -0,0 +1,54 @@
+import express from 'express';
+import { join, dirname } from 'path';
+import { fileURLToPath } from 'url';
+import { getDb } from './db.js';
+
+// Routes
+import indexRouter from './routes/index.js';
+import testRouter from './routes/test.js';
+import statusRouter from './routes/status.js';
+import resultsRouter from './routes/results.js';
+import historyRouter from './routes/history.js';
+import siteRouter from './routes/site.js';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+const app = express();
+const PORT = process.env.PORT || 3132;
+
+// Initialize DB on startup
+getDb();
+
+// View engine
+app.set('views', join(__dirname, 'views'));
+app.set('view engine', 'pug');
+
+// Middleware
+app.use(express.urlencoded({ extended: true }));
+app.use(express.json());
+
+// Static reports
+app.use('/reports', express.static(join(__dirname, 'reports')));
+
+// Routes
+app.use('/', indexRouter);
+app.use('/test', testRouter);
+app.use('/status', statusRouter);
+app.use('/results', resultsRouter);
+app.use('/history', historyRouter);
+app.use('/site', siteRouter);
+
+// 404
+app.use((req, res) => {
+  res.status(404).render('error', { title: '404 Not Found', message: 'Page not found.' });
+});
+
+// Error handler
+app.use((err, req, res, _next) => {
+  console.error(err);
+  res.status(500).render('error', { title: 'Server Error', message: err.message });
+});
+
+app.listen(PORT, () => {
+  console.log(`Speedboard running at http://localhost:${PORT}`);
+});